Warren Buffett’s Berkshire Hathaway Inc said on Thursday it had taken a stake in Suncor Energy Inc, sending the U.S.-listed shares of the oil and gas producer up 4 percent in after-market trading.

Berkshire said in a filing with the Securities and Exchange Commission that it has a stake of 10.8 million shares in the company, representing about 0.7 percent of Suncor’s total outstanding shares, according to Eikon data from Refinitiv.